I have an 04 scab with the 5.4L. Im pretty sure my cats are clogged as I have no power and they are glowing red. I have no interest in removing all of the cats. I would like to remove the rear ones and replace the front ones with high flow ones (specifically magnaflows). Im looking for someone that has done this to confirm if it will or will not throw any codes. I know removing cats isnt legal but all the 05+ f150's only have 2. I also got a qoute from Ford and if they were to replace the entire exhaust it would have only 2 cats like the newer ones. If I do remove the rear ones will I need simulators or are they not effected by the rears? No guesses if possible. Someone who has done this is needed.

 

according to a reliable mechanic i know that works at ford, ford already makes their cats high flow, so it would be pointless to replace with high flow, and you might want to check your air fuel ratio cause if your cats are glowing, it probably means u melted the insides of the cat and you are running too lean

 

I was told the same thing from my friend that owns a exhaust shop

 

Earlier this year I replaced both of mine becaused the engine back fired and collapsed one so I just bought both sides a direct blot on from napa and are made by walker exhaust part number 50553 list for 640.10 payed 295.39 , 53569 list 834.54 payed 385.39 if you know a mechanic well you should get them through him at his cost . I bolted them on myself no code problems even though it is possible .

 

time for an off road mid-pipe!

 

My mechanic told me to go with Walker not a "cheapy" from autozone type stores, they fail. I have heard of "high flow" cats, someone might try to sell you on that. Put cats back on. Read this article;
http://www.fordf150.net/forums/viewtopic.php?t=60187

 

I agree with everything except the lean part. The engine has to be dumping fuel into the exhaust to light off a cat enough to get it to glow red.

 

not necessarily, i know im comparing small to large here but my quad was running very lean and the exhaust turned cherry red, hard to believe that less gas would cause this, but more gas will just clog up the cat, not burn the cat